Getting It Wrong

I wrote this piece about two years ago. At that time I had just completed my second year assisting at the Four Corners Rifle and Pistol Club Range during Hunter Sight-in Days, I have long-since gained a new respect for just how often nimrods can, and do, chamber, and fire, the wrong ammunition in the "right" gun. In fairness, I must admit having been at least peripherally involved in no less than three such fiascoes myself, two within one recent year! Happily, in none of those instances did anyone experience any serious harm or property loss. However, I do know of two instances where chambering and firing the wrong ammunition led to injuries significant enough to end a day's shooting, although neither led to permanent personal injury.

A few examples might enlighten. At hunter's sight-in last year, one shooter, who was unwilling to ask for or to accept help, managed to chamber and fire 20 rounds of 243 ammunition in a 308-chambered rifle. He never did hit the 100-yard target. Hearing the odd report, I observed what he was doing and noted the unusually mild recoil. I then verified the markings on both ammo box and rifle.

Since this "real man" had already declined any of our expert help and had done so in a less than generous manner, "I know what I'm doing, just leave me alone," and since firing 243s in a 308 is extremely unlikely to cause any harm, I felt no shame in allowing him to burn up his entire box of factory fodder. Afterwards, he sat there scratching his head and muttering, "I just don't understand it…." I then gently mentioned, "I suspect the only thing wrong is the ammunition you used." He then barked, "What do you mean!"

I said, "Well, it has been my experience that two-forty-three loads seldom shoot well from a 308-chambered Rifle." His face went pale, then crimson. He then hurriedly loaded his gear and departed.

Later, an elderly man set down at the bench and proceeded to fire 270 loads from a 30-06. Since he had been gracious when asked if he needed any assistance, I stopped him after the third shot. He said he could not understand why he was making a pie plate sized "group" on the target. "This old ought-six has always been a good shooter," he noted. I said, "Well it's just a guess, but maybe it's because you are shooting two-seventy ammo in it." We both had a good laugh and went on to test his intended loads and prove that, yes, indeed, his old '06 was a good shooter.

This year a group entered the parking lot in a large van. Before the van even stopped, people and equipment started pouring forth. When the dust settled, I counted six hunters and eight rifles.

Two evidently identical rifles belonged to one of the hunters. That should have raised my neck hairs but I was busy elsewhere. Five of the shooters signed in and lined up at adjacent benches – six through ten. Soon they were blasting away. Another group, who assured us, "we don't need no stinking help." Well, not in those words, they were at least moderately polite about it. They were just confident and they did have at least one supposedly experienced shooter among their ranks. He happened to own that pair of Browning semi-automatic rifles and was loaning one to his friend who was a novice hunter and shooter. Had I known that detail, it would most certainly have gotten my attention.

The benches and target frames are numbered. Normally the shooter fires at the target matching the number of the bench at which he is seated. I sat down to spot shots on target five. I noted what appeared to be at least two touching holes. Assuming that shooter #5 had already fired several shots, I thought nothing of it until he fired four shots and produced a 6-inch plus group, with holes that were nowhere near that ragged, odd looking hole. As he and I were discussing the fact that he had only fired four shots at what had been a fresh target, the man on bench six came over and asked if I had a cleaning rod.

Upon prompting, he stated that he had a case stuck in the chamber of the Browning semi-auto he was shooting. I said, "Let's try this first. You hold the bolt open. I will reach through from the bottom and try to pry the case free using the screwdriver blade on my Swiss army tool. If that does not work, I will get a dowel from my car." He did, I did and a swollen 270 case fell free from that 7mm Rem Mag chamber. Turns out he had the wrong rifle, the other semi-auto was the 270.

His shot was the one that had formed the odd hole in target five, although he had been shooting at target six. That relatively hard Nosler Partition bullet had not obturated and therefore had not stabilized. It struck the adjacent target while traveling practically sideways. Since the bullet had not swelled to fit the bore, pressure was not as high as it might have been. That may explain why the case had not ruptured. I know of two such instances – 270 in 7mm Rem Mag – where the case failed. In both, the gun was seriously damaged; those shooters had neither the desire nor the inclination to continue shooting.

When I pointed out what had happened and that the shooter was very lucky that he had not removed some, more or less important, portion of his cranium, both he and the owner of the gun (who purported to be an experienced shooter) were incredulous. They were shocked that guns were designed in such a way that such mismatches were even possible. I could not help feeling that such an opinion was inevitable in a society where everything is supposed to be safe and no one is supposed to be responsible for their own actions.

In my youth, a friend and I were busily burning up a bunch of old 45 Colt ammo in our revolvers. Several hundred rounds into the ordeal we managed to run through several cylinders full of 44 Magnum 240-grain SWCs – sounded odd and was not all that accurate!

I once found eighteen, 8mm Mauser cases that had been fired (evidently successfully) in a 270-chambered rifle. One wonders what happened on the nineteenth shot that stopped me from finding twenty of those oddly fireformed cases. I could list several other stories, but these should suffice.

That leads to the heart of this piece. I will attempt to list at least of few of the likely possible combinations where the wrong ammo can be chambered in the "right" gun and with some likelihood that the extractor, case shoulder, case neck, bullet ogive or just the inertia of the round will hold the cartridge against the firing pin sufficiently to allow the firing pin to set off the primer.

I must note that I am only going to consider current (and a few recently discontinued) SAAMI cartridges. I promise you, I will have missed one or more (perhaps dozens of) likely and potentially dangerous mismatches. Equally, it is likely that some of the mismatches I have suggested are not possible in normally chambered guns with normally sized ammunition, However, just because one particular rifle will not chamber one particular mismatched round does not mean that no similarly chambered rifle will chamber any similar test round. Significant variations in case length, neck thickness, bullet ogive, extractor design and chamber tolerances do exist.

ALWAYS VERIFY THAT THE AMMO YOU CHAMBER MATCHES THE CHAMBER IN THE GUN. IF IN DOUBT: DO NOT TRY IT.

Mismatch hazard varies from slight to dire. I do not offer this as an exhaustive listing; rather, it is intended to point out just how many such possibilities exist. I have only listed those combinations where the cartridge is reasonably apt to chamber and fire. I have heard horror stories about mechanical wizards literally hammering a bolt closed on a wrong size cartridge; the theory evidently being that if they can get it in the gun by any means it must be OK to shoot.

Generally, I have ignored many potentially dangerous pistol and revolver mismatches. Equally, I have ignored the myriad additional combinations coming into play when one considers European and other foreign chamberings. Fodder for other articles.

Gun	Some Cartridges that can Possibly be Chambered by Mistake	Possible Consequences
22 WMR	22 BB Cap, 22 CB Cap, 22 Short, 22 Long, 22 Long Rifle	Sidewall rupture
222 Rem Mag	221 Fireball	Headspace rupture
223 Rem	221 Fireball, 222	Headspace rupture
222 Rem Mag	223	Headspace rupture
	222	Headspace rupture
	221 Fireball	Headspace rupture
22 BR	22 PPC	Sidewall rupture
22-250 Rem	22 PPC	Sidewall rupture
220 Swift	225	Sidewall rupture
6 BR	22 PPC, 6 PPC	Sidewall rupture
243 Win	22 PPC, 6 PPC	Sidewall rupture
243 Win	22-250, 6 BR	Headspace rupture
6mm Rem	22-250, 6 BR	Headspace rupture
	22 PPC, 220 Swift, 6 PPC	Headspace or sidewall rupture
	243	Headspace rupture
257 Roberts	6 BR, 22-250, 250 Sav	Headspace rupture
	22 PPC, 220 Swift, 6 PPC, 243	Headspace or sidewall rupture
	6.5-08	Headspace rupture, insufficient neck clearance
25-06 Rem	22-250, 6 BR, 243, 6mm, 250 Sav, 257 Roberts	Headspace rupture
	6.5-08, 7-08, 300 Sav, 308, 358	Headspace rupture, bore obstruction
	22 PPC, 220 Swift, 6 PPC, 35 Rem	Headspace or sidewall rupture, bore obstruction
257 Wby	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06	Headspace or sidewall rupture
	6.5-08, 7-30 Waters, 7-08, 30-30, 300 Sav, 308, 358	Headspace rupture, bore obstruction
	6.5 Mag	Sidewall rupture, bore obstruction
6.5-08	22-250, 6 BR, 250 Sav	Headspace rupture
6.5x55 Swed	22 PPC, 220 Swift, 6 PPC	Headspace or sidewall rupture
	22-250, 6 BR, 243, 6mm, 250 Sav, 6.5-08	Headspace rupture
	300 Sav	Headspace rupture, bore obstruction
264 Win Mag	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08	Sidewall or headspace rupture
	7-30 Waters, 7-08, 7x57, 30-30, 300 Sav, 308, 8x57, 358	Headspace rupture, bore obstruction
	6.5 Mag	Body wall failure
270 Win	22-250, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08	Headspace rupture
	7-08, 7x57, 300 Sav, 308, 358	Headspace rupture, bore obstruction
	22 PPC, 220 Swift, 6 PPC, 35 Rem	Headspace or sidewall rupture, bore obstruction
270 Wby	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08	Sidewall or headspace rupture
	7-30 Waters, 7-08, 7x57, 30-30, 300 Sav, 308, 8x57, 358	Headspace rupture, bore obstruction
	7mm Wby	Insufficient case neck clearance
	6.5 Mag	Body wall failure
7x57mm	22-250, 6 BR, 243, 250 Sav, 6.5-08, 7-08	Headspace rupture
	300 Sav	Headspace rupture, bore obstruction
	22 PPC, 220 Swift, 6 PPC	Headspace or sidewall rupture
7-08 Rem	22-250, 6 BR, 250 Sav	Headspace rupture
284 Win	22 PPC, 6 PPC, 22-250, 220, 6 BR, 243, 6mm, 250, 257, 6.5-08, 7-08, 7x57	Headspace or sidewall rupture
284 Win	300 Sav	Headspace or sidewall rupture, bore obstruction
280 Rem	22 PPC, 220 Swift, 6 PPC, 35 Rem	Sidewall rupture, bore obstruction
	22-250, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08, 270, 7-08, 7x57	Headspace rupture
	300 Sav, 308, 358	Headspace rupture, bore obstruction
7mm Rem Mag 7mm Wby	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08, 270, 7-30 Waters, 7-08, 7x57, 280	Sidewall or headspace rupture
	30-30, 300 Sav, 308, 8x57, 358	Headspace rupture, bore obstruction
	6.5 Mag	Sidewall rupture
30 Carbine	22 Hornet	Headspace or sidewall rupture
300 Savage	22-250, 250 Sav	Headspace rupture
300 Savage	22 PPC, 6 PPC, 30 Rem	Headspace or sidewall rupture
30-40 Krag	225, 7-30 Waters, 30-30	Sidewall rupture
30-40 Krag	30 Rem	Headspace or sidewall rupture

307 Win	22-250, 225, 7-30 Waters, 30-30	Sidewall rupture
307 Win	30 Rem	Headspace or sidewall rupture
308 Win	22 PPC, 6 PPC, 30 Rem	Headspace or sidewall rupture
308 Win	22-250, 250 Sav	Headspace rupture
30-06 Sprg	22-250, 243, 6mm, 250 Sav, 257 Roberts, 6.5-08, 7-08, 7x57, 300 Sav, 308	Headspace rupture
	358	Headspace rupture, bore obstruction
	22 PPC, 6 PPC, 220 Swift, 35 Rem	Headspace or sidewall rupture, bore obstruction
300 H&H Mag 300 Win Mag 300 Wby	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08, 270, 7-30 Waters, 7-08, 7x57, 280, 30-30, 300 Sav, 308, 30-06	Sidewall or headspace rupture
300 H&H Mag 300 Win Mag 300 Wby	8x57, 358	Headspace or sidewall rupture, bore obstruction
300 Win Mag 300 Wby	257 Wby, 6.5 Rem Mag, 264 Win Mag, 270 Wby, 7mm Rem Mag, 7mm Wby, 308 Norma Mag (300 Win Mag in 300 Wby)	Body wall failure
300 Wby	338 Mag	Body wall failure, bore obstruction
30-378 Wby	Almost any conventional belted magnum up to 30-Caliber	Headspace or sidewall rupture
30-378 Wby	338 Mag	Sidewall or headspace rupture, bore obstruction
303 Savage	22 PPC, 6 PPC, 25-35	Headspace or sidewall rupture
303 British	225, 7-30 Waters, 30-30	Sidewall rupture
	30 Rem	Headspace or sidewall rupture
	30-40 Krag	Insufficient case neck clearance
8mm Mauser	22-250, 243, 6mm, 250 Sav, 257 Roberts, 6.5-08, 7-08, 7x57, 300 Sav, 308	Headspace rupture
8mm Mauser	22 PPC, 220 Swift, 6 PPC, 35 Rem	Headspace or sidewall rupture, bore obstruction
8mm Rem Mag	22-250, 220 Swift, 6 BR, 243, 6mm, 250 Sav, 257 Rob, 25-06, 6.5-08, 270, 7-30 Waters, 7-08, 7x57, 280, 30-30, 300 Sav, 308, 30-06, 8x57	Headspace or sidewall rupture
	358, 35 Whelen	Headspace rupture, bore obstruction
	Almost any conventional belted magnum up to 30-caliber